Rolling tarp system

Abstract

A tarp bar may be an alignment, reinforcement, and furling control member, without adding substantial weight or complexity to a rolling tarp system. The tarp bar is not motorized or otherwise powered, and is preferably attached only to the tarp material, a significant distance from the drive bar and parallel to the length of the tarp and the bed/trailer. The tarp bar is recessed or otherwise-concave along its length to allow cradling of, and hence parallel orientation of, an already-rolled portion of the tarp. The tarp bar is preferably broader than said already-rolled portion and the combination of the already-rolled portion received in the tarp bar is a non-cylindrical unit. Subsequent rolling-up of the tarp tends to occur in a cam-like action that maintains more consistent tension all along the length of the tarp, to form a tighter and more even roll.

1 . A rolling tarp system comprising:
 a tarp having a distal portion and a proximal portion;   a drive bar connected to the distal portion of the tarp;   a tarp bar having a length and a longitudinal recess, the tarp bar being connected to the tarp between the distal portion and the proximal portion and distanced from the drive bar and wherein the tarp bar longitudinal recess is generally parallel to the drive bar;   wherein the drive bar is adapted to roll-up said distal portion of the tarp around the drive bar, and, when said drive bar reaches the tarp bar, the drive bar with said distal portion of the tarp rolled around the drive bar is received in the recess of the tarp bar; and   wherein a combined unit of the drive bar, the distal portion rolled around the drive bar, and the tarp bar continue to roll, powered by the drive bar, to roll-up the proximal portion around said combined unit.   
     
     
         2 . The tarp system as in  claim 1 , wherein said tarp bar is rigid all along the length of the tarp bar. 
     
     
         3 . The tarp system as in  claim 1 , comprising only one tarp bar. 
     
     
         4 . The tarp system as in  claim 1 , wherein the tarp bar is not motorized. 
     
     
         5 . The tarp system as in  claim 1 , wherein said tarp bar comprises two elongated members each having a top surface and a bottom surface, and a plurality of connector members fixed to said bottom surface of each of said two elongated bars to space apart said two elongated members from each other and to rigidly fix said two elongated members relative to each other, wherein a space between the two elongated members and above plurality of connector members is said longitudinal recess. 
     
     
         6 . A rolling tarp system comprising:
 a tarp having a distal portion and a proximal portion;   a drive bar connected to the tarp distal portion and having a longitudinal axis, the drive bar adapted to rotate on said longitudinal axis to roll-up the tarp; and   a tarp bar connected to the tarp at a location distanced from the drive bar, the tarp bar having a longitudinal recess parallel to the drive bar longitudinal axis, so that, upon the drive bar rolling-up the distal portion and reaching the tarp bar, the drive bar and the distal portion rolled-around the drive bar are received in said longitudinal recess; and   wherein continued rotation of the drive bar rolls-up said proximal portion around a combination of the drive bar, the distal portion rolled-around the drive bar, and the tarp bar.   
     
     
         7 . The rolling tarp system as in  claim 6 , wherein said combination has a length parallel to the longitudinal axis of the drive bar and a transverse dimension perpendicular to said length of the combination, and wherein said combination is triangular in transverse cross-section. 
     
     
         8 . The rolling tarp system of  claim 6 , wherein the tarp bar is a rigid bar comprising two elongated members and connector members spaced apart along the length of the two elongated members and rigidly fixing the two elongated members together in a single unit, and wherein said longitudinal recess is a space between said two elongated members running the length of said two elongated members. 
     
     
         9 . The rolling tarp system of  claim 6 , wherein:
 said tarp bar has two longitudinal edges;   said combination has a length parallel to the longitudinal axis of the drive bar and a transverse dimension perpendicular to said length of the combination;   said combination is triangular in transverse cross-section; and said two longitudinal edges of the tarp bar are a first triangle corner and a second triangle corner of said triangular transverse cross-section; and   an outer surface of the distal portion rolled-around the drive bar forms a third triangle corner of said triangular transverse cross-section.   
     
     
         10 . The tarp system as in  claim 6 , wherein said tarp bar is rigid all along the length of the tarp bar. 
     
     
         11 . The tarp system as in  claim 6 , comprising only one tarp bar. 
     
     
         12 . The rolling tarp system of  claim 6 , wherein said tarp bar is not motorized. 
     
     
         13 . The rolling tarp system of  claim 6 , further comprising a plurality of trailer bow members that are each bent at a bow corner to form a generally horizontal portion and a generally vertical portion, wherein said tarp rests above said bow members and rolls transverse to the bow members when being rolled-up by the drive bar, said tarp bar being located at said bow corners when the tarp is unrolled. 
     
     
         14 . The rolling tarp system of  claim 13 , wherein said tarp bar has two longitudinal edges and a transverse dimension between said two longitudinal edges, and wherein said transverse dimension is on said bow corners at approximately a 45 degree angle to horizontal when the tarp is unrolled. 
     
     
         15 . A method of rolling-up a side-rolling tarp, the method comprising:
 providing a tarp for covering at least a portion of a trailer or a truck-bed;   connecting a rotatable drive bar to the tarp;   connecting a reinforcing bar to the tarp a distance from the drive bar, the reinforcing bar having a longitudinal recess parallel to the length of the drive bar;   rotating the drive bar to roll-up a first portion of the tarp around the drive bar until the drive bar reaches the reinforcing bar, whereupon the drive bar with said first portion rolled-around the drive bar is received in said longitudinal recess;   continuing to rotate the drive bar to roll-up a second portion of the tarp around a combination of the drive bar with said first portion rolled-around the drive bar and said reinforcing bar;   whereby the reinforcing bar strengthens said combination to limit twisting of the drive bar for even and consistent rolling-up of said second portion.   
     
     
         16 . A method of rolling-up a side-rolling tarp, the method comprising:
 rolling-up a first portion of a side-rolling tarp by rotating a drive bar that is attached to the first portion of the tarp;   resting the drive bar with said first portion rolled-around the drive bar in a longitudinal recess of a reinforcing bar that is attached to the tarp; and   continuing to rotate the drive bar to roll-up a second portion of the tarp around a combination of the drive bar with said first portion rolled-around the drive bar and the reinforcing bar.   
     
     
         17 . A method as in  claim 16 , wherein said combination has a length and a transverse dimension, and the combination is non-circular in transverse cross-section. 
     
     
         18 . The method of  claim 16 , wherein said combination is non-circular in transverse cross-section and said continuing to rotate the drive bar comprises a cam action of incremental, partial-rotations of said combination wherein said tarp wraps tightly on said combination prior to each incremental partial-rotation. 
     
     
         19 . The method of  claim 16 , wherein:
 said reinforcing bar has two longitudinal edges;   said combination has a length parallel to the length of the drive bar and a transverse dimension perpendicular to said length of the combination;   said combination is triangular in transverse cross-section, and said two longitudinal edges of the reinforcing bar form a first triangle corner and a second triangle corner of said triangular transverse cross-section; and   an outer surface of said distal portion rolled-around the drive bar forms a third triangle corner of said triangular transverse cross-section;   so that said rotating the combination comprises a cam action comprising three incremental, partial-rotations corresponding to three sides of the triangular-cross-section combination.   
     
     
         20 . The method of  claim 19 , wherein said cam action comprises said combination flipping over each of the first, second, and third triangle corners at the same time all along the length of the combination, so that the tarp wraps tightly around said combination.